By way of example, such a method and such a device are used in the field of checking and monitoring lithography masks for semiconductor production. The pattern can be, e.g., a marker structure or part of a marker structure on the lithography mask. In order now to check or monitor a lithography mask, the position of the pattern needs to be determined very accurately. In particular, it is of interest as to whether the position thereof deviates from the desired position. Since the semiconductors to be produced are becoming more highly integrated and therefore have ever smaller structures, there is a continuous need for improving the accuracy when determining the position. Moreover, the number of patterns, the positions of which are to be determined on the substrate, is also increasing.